Tornado Watch Posted from Virginia to New Jersey

A tornado watch stretches from northern Virginia to New Jersey, including Washington and Philadelphia, as a line of storms ties up air traffic and threatens flooding across the Northeast.

The watch, meaning the storms are possible, is in effect until 10 p.m. East Coast time, according to the National Weather Service. Flood watches and advisories reach as far north as Maine as heavy rain is expected throughout the region, the agency said.

“We have a large upper-level low dropping into the region; it’s driving a cold front into hot and humid air,” said Mike Pigott, a senior meteorologist at AccuWeather Inc. in State College, Pennsylvania. “Even though the cold front pushes through, the upper level of the system will remain over the Great Lakes for a very, very long time.”

The result may be that the Northeast will have heavy rain and thunderstorms through the middle of next week. The region was inundated by a series of storms earlier this month and the chances of flooding go up with each new one, Pigott said.

Flight delays of almost 2 hours were reported at Newark Liberty International Airport in New Jersey and more than an hour at New York’s LaGuardia and Boston’s Logan International, according to the Federal Aviation Administration.

As of 3:30 p.m., 403 flights into and out of the U.S. had been canceled, including 77 at LaGuardia and 69 at Newark, according to FlightAware, a Houston-based airline tracker.

Pigott said the system over the Great Lakes may start to exit by July 3. He isn’t sure it will be completely gone as the U.S. celebrates the July Fourth holiday.

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